采用标准齿轮测量齿轮分度圆跳动的研究

针对齿轮轴齿轮部位分度圆跳动量的测量,引入了标准齿轮的概念,分析了标准齿轮测量机构应该注意的问题,展望了这种检测方法在实践生产中的应用。     

点线啮合齿轮与渐开线齿轮啮合特性对比分析

以点线啮合齿轮副与渐开线齿轮副为研究对象,建立两种啮合齿轮的仿真模型,综合对比分析了点线啮合齿轮与渐开线齿轮在啮合传动误差、齿面载荷分布、齿面滑动速度分布、齿面接触应力分布、齿根弯曲应力分布、啮合接触迹线分析等方面的啮合特性。分析得知,点线啮合齿轮在上述啮合特性方面明显优于渐开线啮合齿轮。研究为全面理解点线啮合齿轮的传动特性提供了理论依据,对其推广应用具有一定参考价值。     

常见齿轮过渡曲线对应齿轮弯曲应力的比较分析

为了全面而深刻地了解齿轮过渡曲线,延长齿轮的工作寿命,从齿轮加工刀具入手对常见齿轮过渡曲线对应的齿轮弯曲应力进行了有限元分析,并将常规齿轮弯曲应力计算中的齿轮单对齿啮合区上界点引入到有限元载荷计算中,以提高有限元计算精度,最后将有限元计算的齿轮最大弯曲应力点与齿轮危险截面弦齿厚进行了对比,以验证结果的正确性。研究表明,应用齿轮过渡曲线设计方法所生成的齿轮,不但使齿形描述方便,而且使弯曲应力的分析更加准确。     

基于磨削齿轮方式修整齿轮误差的分析

为解决常规齿轮加工过程中所产生的误差,将精密磨齿加工与先进检测技术应用到提高齿轮等级中,通过对造成齿轮加工误差因素的分析,建立了误差因素与齿轮精度指标之间的对应关系,并结合精密磨削齿轮的加工特点及优势,提出了采用精密磨削齿轮改进齿轮精度的方法,即在已有齿轮误差的前提下,结合实验,就其误差成因、磨齿原理、修整方法等方面提出了较为完善的改进办法,并对其进行修整,从而避免了该误差对传动机构精度的影响。研究结果表明:采用精密磨齿方式进行齿轮误差的修整,是有效提高齿轮精度的捷径,在常规方法等级基础上可以提高2~3个等级。     

用齿轮噪声特性诊断齿轮故障的研究

本文是利用齿轮在运转时发生的噪声,通过对其特性分析。诊断齿轮故障的试验研究总结。在专用试验台上对直齿轮疲劳试验后出现的故障现象进行了试验。先连续测取齿轮噪声信号,然后在专用信号分析仪和通用计算机上用FFT幅值谱、功率谱、倒频谱和非线性的最大熵谱、倒熵谱进行分析。结果表明,齿轮故障在这些谱图上都有明显反映,尤其是在倒频谱和倒熵谱图上,可以更明确地诊断齿轮故障。通过对啮合频率谐波的数据分析,指出可以定量诊断齿轮故障。本试验研究为进一步在现场诊断齿轮故障提供了方法和依据。     

浅析微型齿轮与普通齿轮的主要差别

本文较详细地讨论了微型齿轮与普通齿轮的主要差别.文中着重在如下几个方面:国标与模数的范围、基准齿形、侧隙种类、公法线平均长度极限偏差Ew和量柱直径dp,以及中心距极限偏差fa;分析和阐述了微型齿轮与普通齿轮的主要差别.本文对于设计和开发微型齿轮传动,尤其对于微型行星齿轮传动设计具有较大的帮助.     

齿轮传动系统的动力学与模态分析

为了提高齿轮设计的准确性,结合UG软件参数化建模功能,建立齿轮传动三维实体模型。利用ADAMS软件对齿轮传动系统进行了动力学分析,在高速传动中施加实际传动载荷,得到了齿轮传动系统的振动频率范围和高频率点。通过ANSYS Workbench软件对齿轮传动系统和单一齿轮模型进行模态分析,得到齿轮传动系统和齿轮模型的固有频率和振型,通过与动力学分析得到的频率进行对比,验证了齿轮传动系统的设计准确性,从而为今后齿轮的传动分析提供了数据支持,并为传动过程中的故障分析提供了参考。     

改善齿轮噪声的措施

阐述了齿轮噪声产生的机理 ,分析了影响齿轮噪声的一些因素 ,说明要控制齿轮噪声 ,在设计与制造阶段应合理地确定齿轮的结构参数及其制造精度 ,并根据实际情况进行综合利用。     

多齿轮式齿轮泵的齿轮变位设计

迄今为止,齿轮泵的寿命还远远达不到设计要求,这主要是齿轮泵存在较大的径向不平衡力所致,通过在一个齿轮周围对称布置若干个齿轮构成多齿轮式齿轮泵,就可以实现径向力的平衡,大大延长齿轮泵的服役时间,本文综合运用行星传动机构及齿轮泵的有关知识,分析了多齿轮式齿轮泵的齿轮变位问题,为泵的研究和开发提供了一种创新思路。     

齿轮加工误差对齿轮传递运动的影响

本文对齿轮加工误差在齿轮在传动中的表现形式对传动准确性产生的影响进行了分析。     

渐开线行星齿轮啮合力的动态仿真

利用solidworks建立了参数化渐开线齿轮三维实体模型,并导入多体动力学分析软件ADAMS.根据Hertz弹性撞击理论,在齿轮之间施加碰撞力,实现了齿轮啮合.并对行星齿轮啮合过程进行了仿真分析,研究了在不同条件下啮合力的变化情况.     

Numerical analysis on meshing friction characteristics of nano-gear train

The objective of this research work is to provide a systematic method to perform molecular dynamics simulation or evaluation for meshing friction properties approach of micro/nano-gear train in MEMS. A model for meshing friction of micro/nano-gear train is proposed by using molecular dynamics based on investigation about a pair of meshing nano-teeth. The results show that the frictional characteristics in single meshing region are similar to the situation in the normal macro-gears meshing; however, the zero fictional force is not shown on the node of meshing. The maximum of the frictional force becomes larger and larger and the minimum of the frictional force becomes smaller and smaller when the number of the atomic layer in z direction increases. So the curve of the frictional force becomes steeper than the situation in normal macro-gears meshing. The maximum and the minimum of the frictional force are all invariable but the curve of the frictional force becomes steeper when the angular velocity of the powered gear increases. In the other case, there are no any changes in curve of the frictional force when the resisting torque increases.     

The meshing angular velocity and tangential contact force simulation for logarithmic spiral bevel gear based on Hertz elastic contact theory

To obtain the change tendency of output angular velocity and tangential contact force of a gear when the pinion under the step input during meshing of a new type of spiral bevel gear, which is a logarithmic spiral bevel gear, the tooth flank equation of logarithmic spiral bevel gear is deduced based on the formation mechanism of the tooth flank formation. A three-dimensional model of a pair of logarithmic spiral bevel gears whose number of teeth was 37:9, with modules being 4.5 mm, normal pressure angle being 20 degrees and spiral angle being 35 degrees were built and assembled. Based on Hertz elastic contact theory, the calculation formulas and parameters sets of contact force for conventional spiral bevel gear meshing simulation and logarithmic spiral bevel gear meshing simulation were done. Consider the dynamic simulation about meshing angular velocity and tangential contact force for conventional spiral bevel gear meshing and logarithmic spiral bevel gear meshing, respectively. Finally, by analyzing and comparing the simulation data, the results show that under the same input conditions, the fluctuation of the gear angular velocity and tangential contact force of logarithmic spiral bevel gear meshing are smaller than the conventional spiral bevel gear. That is, the transmission stationary of logarithmic spiral bevel gear meshing is superior to conventional spiral bevel gear.     

齿轮传动中啮合冲击的计算分析

在文献[1]所建立的齿轮传动啮合冲击动力学模型的基础上,通过理论分析并编制相应的分析程序,计算了渐开线直齿轮传动中啮入冲击力、冲击速度的变化情况,分析了传动比、模数、载荷等对齿轮传动中冲击力的影响情况。结果表明：(1)随着传动比的增大,齿轮传动中的冲击力随之降低;(2)模数增大,使得轮齿之间的冲击力增大;(3)在其他条件不变时,载荷增大将导致冲击力增大;(4)载荷和速度相比,速度对冲击力的影响较大。     

Meshing stiffness property and meshing status simulation of harmonic drive under transmission loading

The multitooth meshing state of harmonic drive (HD) is an important basic characteristic of its high transformation precision and high bearing capacity. Meshing force distribution affects the load sharing of the tooth during meshing, and theoretical research remains insufficient at present. To calculate the spatial distributed meshing forces and loading backlashes along the axial direction, an iterative algorithm and finite element model (FEM) is proposed to investigate the meshing state under varied transmission loading. The displacement formulae of meshing point under tangential force are derived according to the torsion of the flexspline cylinder and the bending of the tooth. Based on the relationship of meshing forces and circumferential displacements, meshing forces and loading backlashes in three cross-sections are calculated with the algorithm under gradually increased rotation angles of circular spline, and the results are compared with FEM. Owing to the taper deformation of the cup-shaped flexspline, the smallest initial backlash and the earliest meshing point appear in the front cross-section far from the cup bottom, and then the teeth in the middle cross-section of the tooth rim enter the meshing and carry most of the loading. Theoretical and numerical research show that the flexibility is quite different for varied meshing points and tangential force amplitude because of the change of contact status between the flexspline and the wave generator. The meshing forces and torsional stiffness of the HD are nonlinear with the torsional angle.     

Mathematical model and meshing analysis of internal meshing gear transmission with curve element

A new internal meshing gear transmission with curve element is put forward in this paper. The mathematical principle of tooth profile generation is described based on conjugate curves theory. For a given spatial curve, the meshing equation and its conjugated spatial curve under the motion law were derived. Considering the equidistant kinematic method, general internal tooth profiles models were established by the conjugate-curve pair. Numerical example of the internal gear pair was developed according to gear parameters and gear solid models were established by MATLAB and UG software. Motion simulation result shows that the gear pair satisfies point contact condition and design requirements. Meshing analysis of tooth profiles using FEA method was carried out. Stress analysis results of tooth profiles with single point contact and two points contact were, respectively, obtained. The conclusions lay the foundation for multi-point contact generation and tooth profile design. Also, further studies on transmission characteristics and manufacturing technology of the new gear drive will be carried out.

     

Transient meshing performance of gears with different modification coefficients and helical angles using explicit dynamic FEA

The gearbox, as the main part of power transmission of many mechanical systems, plays a critical role for the performance of the system. The transient meshing performance of the gears is dependent on their structural parameters like modification coefficient and helical angle among others. In this paper, the effects of modification coefficients and helical angles on the transient meshing performance of the gears are investigated using the method of explicit dynamic finite element analysis (FEA) in an energy point of view. The relationships between the transient meshing performance and modification coefficient or helical angle of gears are obtained by explicit dynamic simulation. The simulation results demonstrate that explicit dynamic FEA can be used for choosing these structural parameters in the design and manufacture of gears to enhance their transient meshing performance.     

变速传动下的齿轮啮合力计算仿真研究

齿轮啮合力是计算齿轮零件强度、刚度和疲劳寿命的重要参数.通过建立传动系统的力学模型,以Hertz弹性碰撞理论为基础,建立在变速条件下的计算机仿真模型.最后给出某型机械压力机传动系统的计算实例.根据仿真结果可知,在加速条件下,齿轮啮合力随着速度呈指数增长,且指数随着加速度的增加而增大.     

齿式离合器结合过程动态特性的仿真

为了分析齿式离合器齿轮在轴向结合过程中的动态冲击载荷,进而为工程设计提供参考,以存在转速差和轴向相对运动的内啮合齿轮副作为研究模型,采用系统动力学分析软件ADAMS分析了轮齿结合过程的动态特性,给出了完整结合过程的动态转矩、轴向力和转速等关键参数.分析了轮齿结合过程的机理,并基于数值仿真定量分析了主要结构参数和运行参数对内啮合轮齿轴向结合过程及其冲击载荷的影响.结果显示存在转速差和轴向相对运动的齿轮副在结合过程中产生较大的轴向力和转矩冲击值,并且轮齿转速差、结合速度和轴向推力等参数对冲击载荷具有较大影响,该结果可为相关离合器的设计提供依据.